Prefabricated, adjustable stairway, ramp or bridge



Jan. 24, 1967 L. CARTER 3,299,590

PREFABRICATED, ADJUSTABLE STAIRWAY, RAMP OR BRIDGE Filed June 1, 1964 4 Sheets-Sheet 1 v 76 i lam/0y (a/fer W 3 gm W ATTORNEY Jan. 24, 1967 LCARTER 3,299,590

ADJUSTABLE STAIRWAY, RAMP OR BRIDGE PREFABRICATED,

Filed June 1, 1964 4 Sheets-Sheet ATTORNEY PREFABRICATED, ADJUSTABLE STAIRWAY, RAMP OR BRIDGE Filed June 1, 1964 L. CARTER Jan..24,- 1967 4 Sheets-Sheet 5 (or/er INVENTOR. MFW

ATTORNEY L- CARTER Jan. 24, 1967 PREFABRICATED, ADJUSTABLE STAIRWAY, RAMP OR BRIDGE Filed June 1, 1964 4 Sheets5heet 4 United States Patent 3,299,590 PREFABRICATED, ADJUSTABLE STAIRWAY, RAMP 0R BRIDGE Lavoy Carter, 811 Isabella, Houston, Tex. 77002 Filed June 1, 1964, Ser. No. 371,466 Claims. (Cl. 52-183) This invention relates to an adjustable stairway and more particularly to a prefabricated structure which may be used as a stairway, ramp or bridge and which is adjustable to fulfill numerous different conditions of use.

The invention has for an important object the provision of a structure whose parts are fabricated to be assembled to erect a stairway whose height and angle vary to accommodate the same to different locations and conditions of use.

Another object of the invention is to provide a struc ture made up of prefabricated parts designed to be assembled to form a stairway, ramp, bridge or similar device, which is easily adjusted to accommodate the structure to widely differing conditions at the location where the same is to be erected.

A further object of the invention is the provision of a stairway having stringers which may be erected at various angles to adjust the same. for use between upper and lower levels located at different vertical distances and having treads or steps which may be adjusted to horizontal positions in accordance with the angle at which the stringers are disposed, and including means whereby all of the-treads or steps will be positioned at equal vertical distances apart.

Another object of the invention is to provide a stairway having stringers which may be disposed at any desired angle to the horizontal and treads or steps which may be adjusted to horizontal positions and which are connected to the stringers at locations to position all of the treads at equally spaced vertical intervals between which the stairway is erected.

A further object of the invention is the provision of a structure for use as a stairway, ramp, bridge, or the like, made up of component parts which are easily and quickly assembled and adjusted for any of the uses for which the structure is designed, and which are of rugged construction and economical manufacture.

The above objects of the invention and other obvious advantages of the same will be apparent from the following detailed specification of the same when considered with the annexed drawings wherein:

FIGURE 1 is a side elevational view, on a greatly reduced scale illustrating a preferred embodiment of the invention and showing the manner in which the same is erected to form both a stairway and a walkway or bridge in combination;

FIGURE 2A is a fragmentary, side elevational view illustrating the lower end portion of the stairway of the invention and one end of the walkway thereof, showing the connecting means for the same and the manner in which the parts are assembled; 7

FIGURE 2B is an upward continuation of the stairway illustrated in FIGURE 2A;

FIGURE 2C is an upward continuation of the stairway as illustrated in FIGURE 2B, showing the upper end of the stairway and the means by which the same is secured in place;

FIGURE 3 is a cross-sectional view, taken along the line 33 of FIGURE 2A, looking in the direction indicated by the arrows;

FIGURE 4 is a cross-sectional view, taken along the line 44 of FIGURE 2B, looking in the direction indicated by the arrows; and

FIGURE 5 is a cross-sectional view, taken along the 3,299,590 Patented Jan. 24, 1967 line 5--5 of FIGURE 2C, looking in the direction indicated by the arrows.

Referring now to the drawings in greater detail, the invention is illustrated in FIGURE 1 in connection with its use as a combined stairway and walkway, the stairway, generally designated, 10, being shown extending from a lower level or floor L to an upper level or floor U, and the walkway, generally designated 12, extending horizontally away from the lower end of the stairway.

It will, of course, be understood that the stairway 10 may and walkway 12 may be used together or separately, the stairway extending to any height, at any desired angle and having any convenient number of steps or treads, and that the walkway being disposed at any desired angle to the horizontal to form a bridge or ramp.

The stairway 10 is made up of a pair of parallel stringers 12, of channel shape in cross-section, having inturned tions 34 and 36, the perforations of each row being at the portions 16 along the margins of the flanges 18 thereof, between which stringers, treads or steps 20 extend, which are pivotally connected at their opposite ends to the webs 22 of the stringers for vertical swingingadjustment to horizontal positions. The treads or steps are preferably of generally inverted pan shape made up of a channel-shaped member 24 having at each end an angleshaped element 26 suitably attached thereto, as by means of bolts 28. The elements 26 each have a downwardly extended widened flange 30 provided with a perforation for the reception of a bolt 32, by which the tread or step is pivotally connected to the web-22 of the stringer. The flange 30 is also provided with arcuate rows of perforasame radius from the bolt 32, and the Web 22 has perforations, such as that shown at 35, located at the same radius from the bolt 32 as are the rows of perforations 28 and 30, so that a selected one of the perforations of the rows will be in registration with one of the perforations of the web when the tread is horizontal and the tread may be secured in such horizontal position, as by means of a bolt 33, when the stringers are erected at any angle of adjustment to the horizontal.

It will be apparent that by this construction the treads or steps 20 may be moved to horizontal positions when the stringers have been erected, to suit the angle at which the stringers are disposed and thereafter securely bolted in place.

Each of the stringers 14 has at its upper end a connector element or extension 40, best seen in FIGURE 2C, which is extended at one end between the flanges of the stringer and secured thereto in any suitable manner,

as by welding, or the like, the element 40 having sidestringer, which is of generally angle shape, having one arm 60 thereof positioned against a vertical face of a wall W or other support below the upper level or floor U and secured thereto by any suitable means such as the bolts or screws 62 The other arm 64. of the bracket 58 extends away from the wall at right angles thereto and is provided with arcuate rows of perforations 66 and 68. The plate-like portion 46 of the connector element 40 also has perforations located to be brought into registration with certain of the perforations 66 and 68, depending upon the angle to the horizontal at which the stringers are erected, and through which bolts 70 and 72 may be extended to secure the stringers to the wall at the desired angle.

A similar lower end connector element or extension 48 is connected to the lower end of each stringer, which element has side flanges t and 52, best seen in FIGURE 2A, which extend between the side flanges of the stringer, the side flanges 5t) and 52 being cut away to leave an outwardly extending plate-like portion 54 of the web of the element 48 at the outer end thereof.

A lower attaching bracket 74 is provided for each stringer, as best seen in FIGURE 2A, which is of generally angle shape having one arm 76 thereof resting upon the lower level or floor L and secured thereto, as by means of the bolts or screws 78, the other arm 80 of the lower bracket extending upwardly away from the floor L and being provided with two sets of arcuate rows of perforations 82 and 84 and 86 and 88, respectively. The platelike portion 54 of the lower element 48 also has perforations located to be brought into registration with certain of the perforations 82 and 84 of the lower connector element, depending upon the angle to the horizontal to which the stringers are erected, and through which bolts 90 and 92 may be extended to secure the stringers to the floor L.

When the stairs are to be used with a bridge, ramp, or horizontal walkway, such as that designated 12, such structure has stringers or beams .of channel shape, similar to the stringers 14, one of which is shown at 14' in FIG- URE 2A, which beams may each have at each end a connector element similar to the element 48 previously described, and which is similarly provided with perforations in the plate-like portion 54' thereof positioned to be brought into registration with certain of the perforations 86 and 88 of the lower bracket 74, depending upon the angle to the horizontal at which the beams are disposed, and through which bolts 94 and 96 may be extended to secure the beams to the brackets. The perforations of the beams 14 and perforations 86 and 88 of the brackets 74 are preferably located in a manner such that when the beams are secured to the brackets there will be some clearance, such as that shown at 98, between the beams and the lower floor or level L.

The stringers 14 are provided at intervals therealong with plates 100 extending positioned in facing contact with the outer surfaces of the inturned portions of the side flanges of the stringers, as best seen in FIGURES 2B and 4. These plates may conveniently be secured in place by cross-bars 102 positioned against the inner surfaces of the inturned portions of the side flanges of the stringers and bolted to the plates 100, as by means of bolts 104, to clampingly engage such inturned portions between the plates and bars. By this arrangement the plates 100 may be positioned at any desired locations along the lengths of the stringers to support uprights 106 thereon by which a railing 108 is supported above each stringer.

The plates 100 are provided with perforations through which bolts 110 are extended which also extend through the lower end portions of the uprights 106. The plates 100 also have arcuate rows of perforations 112 and 114, as seen in FIGURE 2B, with certain of which upper perforations in the uprights 106 may be brought into registration, depending upon the angle to the horizontal at which the stringers are erected, and through which bolts 116 are extended to hold the uprights vertical.

In installing the treads or steps the treads are attached to the webs of the stringers, by means of the bolts 32, after which the treads are positioned horizontally to bring into registration perforations of the elements 26 with certain of the perforations of the arcuate rows 28 and 30, whereupon the bolts 33 may be inserted to securely hold the steps in horizontal positions. The perforations of each of the rows 28 and are all located at the same radius from the bolts 32, and the perforations 28 and 30 are at-equally spaced arcuate intervals so that the treads may be positioned horizontally in accordance with the angle at which the stringers are erected.

It will be noted that the bolts 32 of each stringer will all be located along a common center line parallel with the longitudinal axis of the stringer. The bolts 32 are also located somewhat below the upper surface of the treads or steps 20, and in order to provide an arrangement in which all of the steps are at the same distance apart, and the lowermost step is at the same height above the floor L as the distance between the steps and the uppermost step is at the same distance below the upper level U as the distance between the steps, the perforations of the arcuate rows 82 and 84 are disposed along arcs whose center is located at a point X, located at the same distance Y below the level of the floor L as the center of the bolt 32 is located below the upper surface of the step 20 and on the common center line of the bolts 32. By so locating the perforations in the upright flange of the lower brackets '74, the first step above the lower level L will be at the same distance as the distance between the steps above.

Similarly, the arcuate rows of perforations 66 and 68 of the upper brackets 58 are positioned along arcs whose center is located at a point Z, which is at the same distance Y below the upper level U, and on the common center line of the bolts 32, so that the uppermost step 20 will be at the same distance below the upper level U as the distance between the steps below.

It will be understood that the perforations 66 and 68 of the upper brackets and the perforations 82 and 84 of the lower brackets may be spaced apart at suitable intervals, such that the stringers may be erected at various angles to the horizontal, and that the perforations 28 and 30 of the tread or step members may be similarly located, so that the treads or steps may be positioned horizontally when the stringers are disposed at any angle for which the stairs are adapted.

In each instance in the sets of arcuate rows of perforations 66 and 68, 82 and 84, and 112 and 114, the perforations of one such row are offset circumferentially relative to the perforations of the other such row, whereby a large number of adjustments may be provided for without positioning the perforations too close together. By this means the strength and rigidity of the material may be adequately maintained while providing relatively close adjustment of the parts.

In erecting the stairs the upper and lower brackets may be secured in place and the stringers attached thereto at the desired angle, whereupon the steps may be positioned between the stringers and bolted thereto with all of the steps positioned horizontally. With the stairs thus erected all of the steps will be at equal vertical distances apart, the lowermost step being at the same distance above the lower level as the distance between the steps above and the uppermost step being below the upper level at the same distance between the steps below.

The herein described structure has a further advantage that the perforations of the steps or treads through which the same are bolted to the stringers are within the webs of the stringers so that the same are out of sight when the structure is erected.

In fabricating the various parts of the perforations of the same may be formed as knock-outs, so that there will be no holes in the parts except those through which the bolts are extended to secure the parts together, thus clearly improving the appearance of the structure. i

It will thus be seen that the invention, constructed and erected as described above, provides a prefabricated, adjustable stairway, walkway, ramp, bridge, or the like, which is designed to be erected between levels which are at different vertical distances apart, with the stairs extending at various angles to the horizontal, while at the same time all of the steps will be located at the same vertical distance apart.

The invention is disclosed herein in connection with a certain specific embodiment of the same, which it will be understood is intended by way of example only, the same being capable of numerous modifications within the spirit and scope of the appended claims.

Having thus clearly shown and described the invention, what is claimed as new and desired to secure by Letters Patent is:

1. In a stairway, spaced apart parallel stringers of generally channel shape extending at an angle to the horizontal between upper and lower floors, with the flanges of one stringer extending away from the flanges of the other stringer, plate means secured to the flanges of each stringer and providing flat plate portions, positioned parallel to the webs of and spaced longitudinally along the stringers, each of said plate portions having an arcuate row of perforations and an opening spaced radially from said perforations, an upright for each of said plate portions having a lower end opening through which a bolt is extended through said opening of the plate portion, and an opening positioned above said lower end opening for registration with a selected one of said perforations and through which a bolt is extended through said selected perforation to hold the upright vertical.

2. In a stairway, channel shaped stringers arranged in spaced apart parallel relation extending at an angle to the horizontal between upper and lower floors, the flanges of one stringer extending away from the flanges of the other stringer and each of the stringers having a vertically disposed plate-like portion located in outwardly spaced parallel relation to its web and having an opening and an arcuate row of perforations each of which is positioned to be in vertical alignment with said opening when the stringer is positioned at a predetermined angle to the horizontal, an upright positioned against the outer surface of said plate-like portion of each stringer and having a lower end opening through which a bolt is extended through the opening of said plate-like portion and an opening positioned above said lower end opening for registration with a selected one of said perforations and through which a bolt is extended through said selected perforation to hold the upright vertical.

3. An adjustable stairway comprising spaced apart parallel stringers extending at an angle to the horizontal between upper and lower floors and having vertically extending wall portions, steps extending horizontally between the stringers and having vertically extending flat end portions, means for pivotally connecting said end portions to said wall portions at equally spaced locations along the stringers and at equally spaced distances below the upper surfaces of the steps to permit said upper surfaces to be adjusted to horizontal positions, a lower bracket of angle shape for the lower end of each stringer positioned with one flange resting upon the lower floor and the other flange extending vertically, said other flange having an arcuate row of perforations whose center is located at a distance below the lower floor level equal to the distance between the upper surfaces of the steps and points at which the steps are pivotally connected to the stringers, said vertical wall portion having an opening positioned for registration with a selected one of said perforations and a bolt extending through said selected perforation to connect the lower end of the stringer to the bracket with the upper surface of the lowermost step positioned at the same distance above said lower floor as the distance between the steps, an upper bracket of angle shape for the upper end of each stringer positioned with one flange thereof resting against a vertical supporting surface below the upper'floor level and the other flange thereof extending outwardly therefrom, said other flange of said upper bracket having an arcuate row of perforations whose center is located at a distance below the upper floor level equal to the distance between the upper surfaces of the steps and the points at which the steps are pivotally connected to the stringers, said vertical wall portion having an opening positioned for registration with a selected one of said perforations of said upper bracket and a bolt 6 extending through said selected perforation of said upper bracket to connect the upper end of the stringer to the upper bracket with the upper surface of the uppermost step positioned at the same distance below said upper floor as the distance between the steps.

4. An adjustable stairway comprising spaced apart parallel stringers extending at an angle to the horizontal between upper and lower floors and having vertically extending wall portions, steps extending horizontally between the stringers and having vertically extending flat end portions, means for pivotally connecting said end portions to said wall portions at equally spaced loca tions along the stringers and at equally spaced distances below the upper surfaces of the steps to permit said upper surfaces to be adjusted to horizontal positions, a lower bracket of angle shape for the lower end of each stringer positioned with one flange resting upon the lower floor and the other flange extending vertically, said vertical flange having arcuate rows of perforations about a center located at a distance :below the lower floor ler'el equal to the distance between the upper surfaces of the steps and the points at which the steps are pivotally connected to the stringers, said vertical wall portion having openings positioned for registration with selected ones of the perforations of said rows and bolts extending through said selected perforations to connect the lower end of the stringer to the bracket with the upper surface of the lowermost step positioned at the same distance above the lower floor as the distance between the steps, an upper bracket of angle shape for the upper end of each stringer positioned with one flange resting on a vertical supporting surface below the upper floor level and the other flange thereof extending outwardly therefrom, said other flange of said upper bracket having arcuate rows of perforations about a center located at a distance below the upper floor level equal to the distances between the upper surfaces of the steps and the points at which the steps are pivotally connected to the stringers, said vertical wall portion having openings positioned for registration with selected ones of the perforations of said upper bracket and bolts extending through said selected perforations of the upper bracket to connect the upper end of the stringer to the upper bracket with the upper surface of the uppermost step positioned at the same distance below said upper floor as the distance between the steps.

5. An adjustable stair-way comprising spaced apart parallel stringers extending at an angle to the horizontal between upper and lower floors and having vertically extending wall portions, steps extending horizontally be tween the stringers and having vertically extending flat end portions, means for pivotally connecting said end portions to said wall portions at equally spaced locations along a common line extending longitudinally along said wall portion of each stringer parallel to such common line of the other stringer and at the same distance from the upper surfaces of the steps to permit said upper surfaces to be adjusted to horizontal positions, a lower bracket of angle shape for the lower end of each stringer positioned with one flange resting upon the lower floor and the other flange extending vertically, said other flange having an arcuate row of perforations whose center is located on said common line at a distance below the lower floor level equal to the distance between the upper surfaces of the steps and the points at which the steps are pivotally connected to the stringers, said vertical wall portion havini-g an opening positioned for registration with a selected one of said perforations and a bolt extending through said selected perforation to connect the lower end of the stringer to the bracket with the upper surface of the lowermost step positioned at the same distance above the lower floor as the distance between the steps, an upper bracket of angle shape for the upper end of each stringer positioned with one flange thereof resting against a vertical supporting surface below the upper floor level and the other flange thereof extending outwardly therefrom, said other flange of said upper bracket having an arcuate row of perforations whose center is located on said common line at a distance below the upper floor level equal to the distance between the upper surfaces of the steps and the points at which the steps are connected to the stringers, said vertical wall portion having an opening positioned for registration with a selected one of the perforations of said upper bracket and a bolt extending through said selected perforation of said upper bracket to connect the upper end of the stringer to the upper bracket with the upper surface of the uppermost step positioned at the same distance below the upper floor as the distance between the steps. I i

8 References Cited by the Examiner UNITED STATES PATENTS 2,867,855 1/1959 Xauter 182-97 FOREIGN PATENTS 807,022 10/ 195 1 Germany. 949,260 9/1956 Germany. 91,809 6/ 195 8 Norway.

OTHER REFERENCES Stavanger, German printed application No. 1,065,747, September 1959.

HARRISON R. MOSELEY, Primary Examiner. KENNETH DOWNEY, Examiner. 

1. IN A STAIRWAY, SPACED APART PARALLEL STRINGERS OF GENERALLY CHANNEL SHAPE EXTENDING AT AN ANGLE TO THE HORIZONTAL BETWEEN UPPER AND LOWER FLOORS, WITH THE FLANGES OF ONE STRINGER EXTENDING AWAY FROM THE FLANGES OF THE OTHER STRINGER, PLATE MEANS SECURED TO THE FLANGES OF EACH STRINGER AND PROVIDING FLAT PLATE PORTIONS, POSITIONED PARALLEL TO THE WEBS OF AND SPACED LONGITUDINALLY ALONG THE STRINGERS, EACH OF SAID PLATE PORTIONS HAVING AN ARCUATE ROW OF PERFORATIONS AND AN OPENING SPACED RADIALLY FROM SAID PERFORATIONS, AN UPRIGHT FOR EACH OF SAID PLATE PORTIONS HAVING A LOWER END OPENING THROUGH WHICH A BOLT IS EXTENDED THROUGH SAID OPENING OF THE PLATE PORTION, AND 